The opposition is count on enough voter turn-out so that the required quorum of 50% plus one vote [AFP]

Italians began voting in four referendums which could a new against Prime Minister Silvio Berlusconi, blow, which last month is reeling from heavy local election.

In advance of the Sunday led a spirited campaign to the voters of their ballots to the questions the center-left opposition, which take concerning the privatization of water utilities, nuclear energy and whether ministers participating in processes against them may be exempted.

A key question will be whether enough voters will be to ensure that the necessary quorum of 50% plus one vote.

But if she remove yes votes of existing laws, is likely the result have impact on militant Berlusconi's centre right coalition.

"The political fate of those who have taken a stand is situated behind the numbers" Il Sole 24 ore, Italy's leading business daily, said on Sunday.

"It is clear that a wave of"Yes"votes a shock, perhaps the last one for his (Berlusconi's) premiership and even his leadership his party leads."

Opposition encouraged

At 10: 00 GMT on Sunday, up to 12 percent of the voting ballots, cast aluminium, had the the opposition support the quorum would be achieved by Monday afternoon, if that was two days the vote ends.

A quorum would be a setback for Berlusconi because he said he would not vote and some of his ministers have urged voters to boycott.

For some of the voices are a way to demonstrate their disappointment on Berlusconi himself, a sex scandal and three studies fraud is facing.

If the quorum is reached, it would mean that "more than half of Italians have a finger against him," said IL sole.

The referendum on nuclear power reactor which is on the most emotive of the four, after the disaster in Fukushima Prefecture, Japan in March.

Polls say that the most Italians against nuclear energy, unsafe in a country holding vulnerable to earthquakes.

Nuclear power proponents

Berlusconi is a big proponent of nuclear power, which says Center-right essential for the future of a country is, which imports almost all its energy.

Last year, the Government passed a law to restart a programme on nuclear energy, which was stopped by an another referendum in 1987.

Aware that likely backlash to Fukushima, has the Government suspended the plans, but a referendum could block nuclear power for decades.

A further referendum would lift, the "legitimate" obstacle which allows Ministers to trial hearings against them to skip, if they are economy, by the Government which Berlusconi's critics say for his personal advantage is.

Two others concern the privatisation of water utilities. The Government says that the privatization is to finance better services. Opponents say, would only cause higher prices.